I got iPhone4 with iOS 4.3.3 and baseband 4.10.01. Unlocked it with Gevey Ultra SIM and using nicely with Bangladeshi network GP (South Asian region).
After getting some idea about jailbreaking, curious to update the OS by keeping baseband unchanged. But mistakenly baseband also changed to 4.12.05. Jailbreak with "iPhone3,1_6.0_10A403_Restore.ipsw" but now unable to use gevey SIM anymore. Now if I want to make the iphone return to baseband 4.10.01 by keeping any OS, how to do? or what best solution is available for me for the current situation? Please reply urgently/ Thanks